/Engine/Plugins/Animation/ControlRig/Source/ControlRig/Public/Rigs/RigHierarchyDefines.h
enum ERigHierarchyNotification { ElementAdded, ElementRemoved, ElementRenamed, ElementSelected, ElementDeselected, ParentChanged, HierarchyReset, ControlSettingChanged, ControlVisibilityChanged, ControlDrivenListChanged, ControlShapeTransformChanged, ParentWeightsChanged, InteractionBracketOpened, InteractionBracketClosed, ElementReordered, Max, }